prime number in c
// C program to check if a
// number is prime
#include <stdio.h>
#include<math.h>
int main()
{
int n, i, flag = 1;
// Ask user for input
printf("Enter a number: \n");
// Store input number in a variable
scanf("%d", &n);
// Iterate from 2 to n/2
for (i = 2; i <= sqrt(n); i++) {
// If n is divisible by any number between
// 2 and n/2, it is not prime
if (n % i == 0) {
flag = 0;
break;
}
}
if(n<=1)
flag=0;
else if(n==2)
flag=1;
if (flag == 1) {
printf("%d is a prime number", n);
}
else {
printf("%d is not a prime number", n);
}
return 0;
}
#include <stdio.h>
int main()
{
int i, num, p = 0;
printf("Please enter a number: \n");
scanf("%d", &num);
for(i=1; i<=num; i++)
{
if(num%i==0)
{
p++;
}
}
if(p==2)
{
printf("Entered number is %d "\
"and it is a prime number.",num);
}
else
{
printf("Entered number is %d "\
"and it is not a prime number.",num);
}
}
